【摘要】 地基动刚度随频率的变化直接影响地下管线的反应,为此,利用Mindlin解和弹性半空间动力基本解分别求得地基的静刚度和动刚度,然后采用随机振动的虚拟激励法计算了均匀介质中地下管线纵向和横向的地震响应.研究结果表明,随着埋深的增大,地基动刚度对频率的变化越来越敏感,与静刚度有明显差别;地基静刚度可近似替代动刚度的根本原因是地面位移自功率谱的低频特性,即地震输入的地面位移自功率谱的有效值均在低频区,而高频部分几乎为零.更多还原

【Abstract】 The response of underground pipeline is affected directly by the variation of dynamic stiffness of founda-tion with frequency.Based on Mindlin solution and dynamic basic solution of elastic half-space,static stiffness and dynamic stiffness of foundation were obtained respectively,then seismic responses of underground pipeline in both longitudinal and lateral directions in uniform medium were calculated respectively by pseudo-excitation method in random vibration theory.The results show that with the increase of buried depth,dynamic stiffness is more and more sensitive to the change of frequency,and is obviously different from the static one;and essentially due to the low-frequency characteristic of auto-power spectral density(PSD) function of ground displacement,namely,regarded as seismic input,auto-PSD function of ground displacement is effective in the low-frequency range,and almost zero in the high-frequency range,dynamic stiffness could be replaced approximately by the static one.更多还原